1. Field of Invention
The present invention relates to elastic endless crawlers for earth-moving machines and the like.
2. Description of the Prior Art
Motor vehicles such as conventional earth-moving machines are so constructed, as shown in FIG. 1, that an elastic endless crawler 100 is held between a drive tumbler 1 and a take-up tumbler 2, and lower rollers 3 roll on an inner surface of the elastic endless crawler 100. In addition, lugs 4 are provided on an outer surface of the elastic endless crawler 100. Many cores 6 are embedded in the elastic endless crawler 100 at a right angle to the longitudinal direction of a crawler body 5 so that they are parallel to one another, as shown in FIG. 2, and engagement holes 7 are provided between the cores 6, so that teeth of the drive tumbler 1 engage with the engagement holes. Also, main cord layers 8 consisting of settl cords, etc. are embedded in the crawler body 5. Additionally, protrusions 6A of the cores 6 are provided to prevent the lower rollers 3 from running off the crawler.
In conventional elastic endless crawlers as shown in FIGS. 1 and 2, when the motor vehicle travels obliquely on a slope, encounters rugged terrain, circles around, or the like, the lower rollers tend to run off the crawler, because the elastic endless crawler clings to the ground while the vehicle continues moving, whereby the elastic endless crawler is pushed relative to the motor vehicle in the transverse direction. That is, when a transverse force F acts on the elastic endless crawler 100 from the transverse direction against the width of the crawler, the crawler deviates from the center line of the motor vehicle, and consequently a slip 200 occurs as shown in FIG. 3.